Compound archery bows have become increasingly popular for hunting and target shooting in recent years. These bows use tension cables which extend over eccentric pulleys revolvably mounted to the bow limbs to provide a mechanical advantage during the drawback and release of a bow string.
The compound bow cable includes a central, or bow string, portion for reception of the arrow. A pair of tension cable portions are connected to the ends of the bow string and extend over the eccentrically mounted pulleys. The tension cable portions typically cross one another between the limbs and attach to the bow limb opposite the pulley over which the respective tension cable portion extends. As the bow string is being drawn, the draw weight or force applied to the bow increases to a maximum draw weight and reduces to a lower draw weight at the full draw position due to the eccentric mounting of the pulleys. Accordingly, when the bow string is in the full dry position, maximum potential energy is stored in the bow while the force required to maintain the bow string in the full draw position is less than the maximum draw weight of the bow. In other words, maximum energy is stored in the limbs without requiring maximum force to be applied to the bow string to hold it at the full draw position. This permits the archer to maintain aim on his target prior to release for a longer time and without undue strain for producing a better shot.
Many devices have been developed for attaching the end of each tension cable to the bow. One such method simply attaches the ends of the tension cables directly to the bow limb by bolts. Other versions secure the inside cables to the bow limbs by means of a yoke member which in turn is secured by a yoke cable to the axle upon which the respective eccentric pulley is rotatably mounted. Anchoring devices such as these are shown in U.S. Pat. Nos. 4,546,754 to Smith; 4,440,142 to Simonds; 4,337,749 to Barna; 4,333,443 to Roelle; 4,300,521 to Schmidt; and 4,064,862 to Groner.
For example, the 4,440,142 patent to Simonds discloses a yoke cable connected at both its ends to a pulley axle which rotatably supports an eccentrically mounted pulley. The cable extends about a perimetric edge portion of a disk-like yoke for securing the disk relative to the axle. A plurality of attachment grooves are formed in the disk which are disposed at varying distances from the disk center. An end of the tension cable extends through the center of the disk and is received by any one of these attachment portions, and is looped back to itself and fixedly secured by a clasp or sleeve-like member. Such an anchoring device enables the tension in the tension cable to be adjusted by changing which of the attachment portions in which the loop in the tension cable is received.
Such a yoke structure is not without drawbacks. For example, to change the tension cable to a different attachment portion in the disk, tension in the cable must be released to enable the cable to be removed from the existing attachment portion. Additionally, each of the attachment portions is set at some fixed distance from the center which enables only a small number of specific finite tension adjustments to be made with a given disk.
Accordingly, a need remains for an improved compound bow having a tension cable anchor which overcomes the above-described drawbacks.